Class Character
- java.lang.Object
-
- java.lang.Character
- All Implemented Interfaces:
-
Serializable
,Comparable<Character>
public final class Character extends Object implements Serializable, Comparable<Character>
The Character
class wraps a value of the primitive type char
in an object. An object of class Character
contains a single field whose type is char
.
In addition, this class provides a large number of static methods for determining a character's category (lowercase letter, digit, etc.) and for converting characters from uppercase to lowercase and vice versa.
Unicode Conformance
The fields and methods of class Character
are defined in terms of character information from the Unicode Standard, specifically the UnicodeData file that is part of the Unicode Character Database. This file specifies properties including name and category for every assigned Unicode code point or character range. The file is available from the Unicode Consortium at http://www.unicode.org.
The Java SE 11 Platform uses character information from version 10.0 of the Unicode Standard, with an extension. The Java SE 11 Platform allows an implementation of class Character
to use the Japanese Era code point, U+32FF
, from the first version of the Unicode Standard after 10.0 that assigns the code point. Consequently, the behavior of fields and methods of class Character
may vary across implementations of the Java SE 11 Platform when processing the aforementioned code point ( outside of version 10.0 ), except for the following methods that define Java identifiers: isJavaIdentifierStart(int)
, isJavaIdentifierStart(char)
, isJavaIdentifierPart(int)
, and isJavaIdentifierPart(char)
. Code points in Java identifiers must be drawn from version 10.0 of the Unicode Standard.
Unicode Character Representations
The char
data type (and therefore the value that a Character
object encapsulates) are based on the original Unicode specification, which defined characters as fixed-width 16-bit entities. The Unicode Standard has since been changed to allow for characters whose representation requires more than 16 bits. The range of legal code points is now U+0000 to U+10FFFF, known as Unicode scalar value. (Refer to the definition of the U+n notation in the Unicode Standard.)
The set of characters from U+0000 to U+FFFF is sometimes referred to as the Basic Multilingual Plane (BMP). Characters whose code points are greater than U+FFFF are called supplementary characters. The Java platform uses the UTF-16 representation in char
arrays and in the String
and StringBuffer
classes. In this representation, supplementary characters are represented as a pair of char
values, the first from the high-surrogates range, (\uD800-\uDBFF), the second from the low-surrogates range (\uDC00-\uDFFF).
A char
value, therefore, represents Basic Multilingual Plane (BMP) code points, including the surrogate code points, or code units of the UTF-16 encoding. An int
value represents all Unicode code points, including supplementary code points. The lower (least significant) 21 bits of int
are used to represent Unicode code points and the upper (most significant) 11 bits must be zero. Unless otherwise specified, the behavior with respect to supplementary characters and surrogate char
values is as follows:
- The methods that only accept a
char
value cannot support supplementary characters. They treatchar
values from the surrogate ranges as undefined characters. For example,Character.isLetter('\uD840')
returnsfalse
, even though this specific value if followed by any low-surrogate value in a string would represent a letter. - The methods that accept an
int
value support all Unicode characters, including supplementary characters. For example,Character.isLetter(0x2F81A)
returnstrue
because the code point value represents a letter (a CJK ideograph).
In the Java SE API documentation, Unicode code point is used for character values in the range between U+0000 and U+10FFFF, and Unicode code unit is used for 16-bit char
values that are code units of the UTF-16 encoding. For more information on Unicode terminology, refer to the Unicode Glossary.
- Since:
- 1.0
- See Also:
- Serialized Form
Nested Classes
Modifier and Type | Class | Description |
---|---|---|
static class | Character.Subset | Instances of this class represent particular subsets of the Unicode character set. |
static class | Character.UnicodeBlock | A family of character subsets representing the character blocks in the Unicode specification. |
static class | Character.UnicodeScript | A family of character subsets representing the character scripts defined in the Unicode Standard Annex #24: Script Names. |
Fields
Modifier and Type | Field | Description |
---|---|---|
static int | BYTES | The number of bytes used to represent a |
static byte | COMBINING_SPACING_MARK | General category "Mc" in the Unicode specification. |
static byte | CONNECTOR_PUNCTUATION | General category "Pc" in the Unicode specification. |
static byte | CONTROL | General category "Cc" in the Unicode specification. |
static byte | CURRENCY_SYMBOL | General category "Sc" in the Unicode specification. |
static byte | DASH_PUNCTUATION | General category "Pd" in the Unicode specification. |
static byte | DECIMAL_DIGIT_NUMBER | General category "Nd" in the Unicode specification. |
static byte | DIRECTIONALITY_ARABIC_NUMBER | Weak bidirectional character type "AN" in the Unicode specification. |
static byte | DIRECTIONALITY_BOUNDARY_NEUTRAL | Weak bidirectional character type "BN" in the Unicode specification. |
static byte | DIRECTIONALITY_COMMON_NUMBER_SEPARATOR | Weak bidirectional character type "CS" in the Unicode specification. |
static byte | DIRECTIONALITY_EUROPEAN_NUMBER | Weak bidirectional character type "EN" in the Unicode specification. |
static byte | DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR | Weak bidirectional character type "ES" in the Unicode specification. |
static byte | DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR | Weak bidirectional character type "ET" in the Unicode specification. |
static byte | DIRECTIONALITY_FIRST_STRONG_ISOLATE | Weak bidirectional character type "FSI" in the Unicode specification. |
static byte | DIRECTIONALITY_LEFT_TO_RIGHT | Strong bidirectional character type "L" in the Unicode specification. |
static byte | DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING | Strong bidirectional character type "LRE" in the Unicode specification. |
static byte | DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE | Weak bidirectional character type "LRI" in the Unicode specification. |
static byte | DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE | Strong bidirectional character type "LRO" in the Unicode specification. |
static byte | DIRECTIONALITY_NONSPACING_MARK | Weak bidirectional character type "NSM" in the Unicode specification. |
static byte | DIRECTIONALITY_OTHER_NEUTRALS | Neutral bidirectional character type "ON" in the Unicode specification. |
static byte | DIRECTIONALITY_PARAGRAPH_SEPARATOR | Neutral bidirectional character type "B" in the Unicode specification. |
static byte | DIRECTIONALITY_POP_DIRECTIONAL_FORMAT | Weak bidirectional character type "PDF" in the Unicode specification. |
static byte | DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE | Weak bidirectional character type "PDI" in the Unicode specification. |
static byte | DIRECTIONALITY_RIGHT_TO_LEFT | Strong bidirectional character type "R" in the Unicode specification. |
static byte | DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC | Strong bidirectional character type "AL" in the Unicode specification. |
static byte | DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING | Strong bidirectional character type "RLE" in the Unicode specification. |
static byte | DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE | Weak bidirectional character type "RLI" in the Unicode specification. |
static byte | DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE | Strong bidirectional character type "RLO" in the Unicode specification. |
static byte | DIRECTIONALITY_SEGMENT_SEPARATOR | Neutral bidirectional character type "S" in the Unicode specification. |
static byte | DIRECTIONALITY_UNDEFINED | Undefined bidirectional character type. |
static byte | DIRECTIONALITY_WHITESPACE | Neutral bidirectional character type "WS" in the Unicode specification. |
static byte | ENCLOSING_MARK | General category "Me" in the Unicode specification. |
static byte | END_PUNCTUATION | General category "Pe" in the Unicode specification. |
static byte | FINAL_QUOTE_PUNCTUATION | General category "Pf" in the Unicode specification. |
static byte | FORMAT | General category "Cf" in the Unicode specification. |
static byte | INITIAL_QUOTE_PUNCTUATION | General category "Pi" in the Unicode specification. |
static byte | LETTER_NUMBER | General category "Nl" in the Unicode specification. |
static byte | LINE_SEPARATOR | General category "Zl" in the Unicode specification. |
static byte | LOWERCASE_LETTER | General category "Ll" in the Unicode specification. |
static byte | MATH_SYMBOL | General category "Sm" in the Unicode specification. |
static int | MAX_CODE_POINT | The maximum value of a Unicode code point, constant |
static char | MAX_HIGH_SURROGATE | The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant |
static char | MAX_LOW_SURROGATE | The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant |
static int | MAX_RADIX | The maximum radix available for conversion to and from strings. |
static char | MAX_SURROGATE | The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant |
static char | MAX_VALUE | The constant value of this field is the largest value of type |
static int | MIN_CODE_POINT | The minimum value of a Unicode code point, constant |
static char | MIN_HIGH_SURROGATE | The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant |
static char | MIN_LOW_SURROGATE | The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant |
static int | MIN_RADIX | The minimum radix available for conversion to and from strings. |
static int | MIN_SUPPLEMENTARY_CODE_POINT | The minimum value of a Unicode supplementary code point, constant |
static char | MIN_SURROGATE | The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant |
static char | MIN_VALUE | The constant value of this field is the smallest value of type |
static byte | MODIFIER_LETTER | General category "Lm" in the Unicode specification. |
static byte | MODIFIER_SYMBOL | General category "Sk" in the Unicode specification. |
static byte | NON_SPACING_MARK | General category "Mn" in the Unicode specification. |
static byte | OTHER_LETTER | General category "Lo" in the Unicode specification. |
static byte | OTHER_NUMBER | General category "No" in the Unicode specification. |
static byte | OTHER_PUNCTUATION | General category "Po" in the Unicode specification. |
static byte | OTHER_SYMBOL | General category "So" in the Unicode specification. |
static byte | PARAGRAPH_SEPARATOR | General category "Zp" in the Unicode specification. |
static byte | PRIVATE_USE | General category "Co" in the Unicode specification. |
static int | SIZE | The number of bits used to represent a |
static byte | SPACE_SEPARATOR | General category "Zs" in the Unicode specification. |
static byte | START_PUNCTUATION | General category "Ps" in the Unicode specification. |
static byte | SURROGATE | General category "Cs" in the Unicode specification. |
static byte | TITLECASE_LETTER | General category "Lt" in the Unicode specification. |
static Class<Character> | TYPE | The |
static byte | UNASSIGNED | General category "Cn" in the Unicode specification. |
static byte | UPPERCASE_LETTER | General category "Lu" in the Unicode specification. |
Constructors
Constructor | Description |
---|---|
Character(char value) | Deprecated. It is rarely appropriate to use this constructor. |
Methods
Modifier and Type | Method | Description |
---|---|---|
static int | charCount(int codePoint) | Determines the number of |
char | charValue() | Returns the value of this |
static int | codePointAt(char[] a,
int index) | Returns the code point at the given index of the |
static int | codePointAt(char[] a,
int index,
int limit) | Returns the code point at the given index of the |
static int | codePointAt(CharSequence seq,
int index) | Returns the code point at the given index of the |
static int | codePointBefore(char[] a,
int index) | Returns the code point preceding the given index of the |
static int | codePointBefore(char[] a,
int index,
int start) | Returns the code point preceding the given index of the |
static int | codePointBefore(CharSequence seq,
int index) | Returns the code point preceding the given index of the |
static int | codePointCount(char[] a,
int offset,
int count) | Returns the number of Unicode code points in a subarray of the |
static int | codePointCount(CharSequence seq,
int beginIndex,
int endIndex) | Returns the number of Unicode code points in the text range of the specified char sequence. |
static int | codePointOf(String name) | Returns the code point value of the Unicode character specified by the given Unicode character name. |
static int | compare(char x,
char y) | Compares two |
int | compareTo(Character anotherCharacter) | Compares two |
static int | digit(char ch,
int radix) | Returns the numeric value of the character |
static int | digit(int codePoint,
int radix) | Returns the numeric value of the specified character (Unicode code point) in the specified radix. |
boolean | equals(Object obj) | Compares this object against the specified object. |
static char | forDigit(int digit,
int radix) | Determines the character representation for a specific digit in the specified radix. |
static byte | getDirectionality(char ch) | Returns the Unicode directionality property for the given character. |
static byte | getDirectionality(int codePoint) | Returns the Unicode directionality property for the given character (Unicode code point). |
static String | getName(int codePoint) | Returns the Unicode name of the specified character |
static int | getNumericValue(char ch) | Returns the |
static int | getNumericValue(int codePoint) | Returns the |
static int | getType(char ch) | Returns a value indicating a character's general category. |
static int | getType(int codePoint) | Returns a value indicating a character's general category. |
int | hashCode() | Returns a hash code for this |
static int | hashCode(char value) | Returns a hash code for a |
static char | highSurrogate(int codePoint) | Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. |
static boolean | isAlphabetic(int codePoint) | Determines if the specified character (Unicode code point) is an alphabet. |
static boolean | isBmpCodePoint(int codePoint) | Determines whether the specified character (Unicode code point) is in the Basic Multilingual Plane (BMP). |
static boolean | isDefined(char ch) | Determines if a character is defined in Unicode. |
static boolean | isDefined(int codePoint) | Determines if a character (Unicode code point) is defined in Unicode. |
static boolean | isDigit(char ch) | Determines if the specified character is a digit. |
static boolean | isDigit(int codePoint) | Determines if the specified character (Unicode code point) is a digit. |
static boolean | isHighSurrogate(char ch) | Determines if the given |
static boolean | isIdentifierIgnorable(char ch) | Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier. |
static boolean | isIdentifierIgnorable(int codePoint) | Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier. |
static boolean | isIdeographic(int codePoint) | Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard. |
static boolean | isISOControl(char ch) | Determines if the specified character is an ISO control character. |
static boolean | isISOControl(int codePoint) | Determines if the referenced character (Unicode code point) is an ISO control character. |
static boolean | isJavaIdentifierPart(char ch) | Determines if the specified character may be part of a Java identifier as other than the first character. |
static boolean | isJavaIdentifierPart(int codePoint) | Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character. |
static boolean | isJavaIdentifierStart(char ch) | Determines if the specified character is permissible as the first character in a Java identifier. |
static boolean | isJavaIdentifierStart(int codePoint) | Determines if the character (Unicode code point) is permissible as the first character in a Java identifier. |
static boolean | isJavaLetter(char ch) | Deprecated. Replaced by isJavaIdentifierStart(char). |
static boolean | isJavaLetterOrDigit(char ch) | Deprecated. Replaced by isJavaIdentifierPart(char). |
static boolean | isLetter(char ch) | Determines if the specified character is a letter. |
static boolean | isLetter(int codePoint) | Determines if the specified character (Unicode code point) is a letter. |
static boolean | isLetterOrDigit(char ch) | Determines if the specified character is a letter or digit. |
static boolean | isLetterOrDigit(int codePoint) | Determines if the specified character (Unicode code point) is a letter or digit. |
static boolean | isLowerCase(char ch) | Determines if the specified character is a lowercase character. |
static boolean | isLowerCase(int codePoint) | Determines if the specified character (Unicode code point) is a lowercase character. |
static boolean | isLowSurrogate(char ch) | Determines if the given |
static boolean | isMirrored(char ch) | Determines whether the character is mirrored according to the Unicode specification. |
static boolean | isMirrored(int codePoint) | Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification. |
static boolean | isSpace(char ch) | Deprecated. Replaced by isWhitespace(char). |
static boolean | isSpaceChar(char ch) | Determines if the specified character is a Unicode space character. |
static boolean | isSpaceChar(int codePoint) | Determines if the specified character (Unicode code point) is a Unicode space character. |
static boolean | isSupplementaryCodePoint(int codePoint) | Determines whether the specified character (Unicode code point) is in the supplementary character range. |
static boolean | isSurrogate(char ch) | Determines if the given |
static boolean | isSurrogatePair(char high,
char low) | Determines whether the specified pair of |
static boolean | isTitleCase(char ch) | Determines if the specified character is a titlecase character. |
static boolean | isTitleCase(int codePoint) | Determines if the specified character (Unicode code point) is a titlecase character. |
static boolean | isUnicodeIdentifierPart(char ch) | Determines if the specified character may be part of a Unicode identifier as other than the first character. |
static boolean | isUnicodeIdentifierPart(int codePoint) | Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character. |
static boolean | isUnicodeIdentifierStart(char ch) | Determines if the specified character is permissible as the first character in a Unicode identifier. |
static boolean | isUnicodeIdentifierStart(int codePoint) | Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier. |
static boolean | isUpperCase(char ch) | Determines if the specified character is an uppercase character. |
static boolean | isUpperCase(int codePoint) | Determines if the specified character (Unicode code point) is an uppercase character. |
static boolean | isValidCodePoint(int codePoint) | Determines whether the specified code point is a valid Unicode code point value. |
static boolean | isWhitespace(char ch) | Determines if the specified character is white space according to Java. |
static boolean | isWhitespace(int codePoint) | Determines if the specified character (Unicode code point) is white space according to Java. |
static char | lowSurrogate(int codePoint) | Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. |
static int | offsetByCodePoints(char[] a,
int start,
int count,
int index,
int codePointOffset) | Returns the index within the given |
static int | offsetByCodePoints(CharSequence seq,
int index,
int codePointOffset) | Returns the index within the given char sequence that is offset from the given |
static char | reverseBytes(char ch) | Returns the value obtained by reversing the order of the bytes in the specified |
static char[] | toChars(int codePoint) | Converts the specified character (Unicode code point) to its UTF-16 representation stored in a |
static int | toChars(int codePoint,
char[] dst,
int dstIndex) | Converts the specified character (Unicode code point) to its UTF-16 representation. |
static int | toCodePoint(char high,
char low) | Converts the specified surrogate pair to its supplementary code point value. |
static char | toLowerCase(char ch) | Converts the character argument to lowercase using case mapping information from the UnicodeData file. |
static int | toLowerCase(int codePoint) | Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file. |
String | toString() | Returns a |
static String | toString(char c) | Returns a |
static String | toString(int codePoint) | Returns a |
static char | toTitleCase(char ch) | Converts the character argument to titlecase using case mapping information from the UnicodeData file. |
static int | toTitleCase(int codePoint) | Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file. |
static char | toUpperCase(char ch) | Converts the character argument to uppercase using case mapping information from the UnicodeData file. |
static int | toUpperCase(int codePoint) | Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file. |
static Character | valueOf(char c) | Returns a |
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Fields
MIN_RADIX
public static final int MIN_RADIX
The minimum radix available for conversion to and from strings. The constant value of this field is the smallest value permitted for the radix argument in radix-conversion methods such as the digit
method, the forDigit
method, and the toString
method of class Integer
.
- See Also:
-
digit(char, int)
,forDigit(int, int)
,Integer.toString(int, int)
,Integer.valueOf(String)
, Constant Field Values
MAX_RADIX
public static final int MAX_RADIX
The maximum radix available for conversion to and from strings. The constant value of this field is the largest value permitted for the radix argument in radix-conversion methods such as the digit
method, the forDigit
method, and the toString
method of class Integer
.
- See Also:
-
digit(char, int)
,forDigit(int, int)
,Integer.toString(int, int)
,Integer.valueOf(String)
, Constant Field Values
MIN_VALUE
public static final char MIN_VALUE
The constant value of this field is the smallest value of type char
, '\u0000'
.
- Since:
- 1.0.2
- See Also:
- Constant Field Values
MAX_VALUE
public static final char MAX_VALUE
The constant value of this field is the largest value of type char
, '\uFFFF'
.
- Since:
- 1.0.2
- See Also:
- Constant Field Values
TYPE
public static final Class<Character> TYPE
The Class
instance representing the primitive type char
.
- Since:
- 1.1
UNASSIGNED
public static final byte UNASSIGNED
General category "Cn" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
UPPERCASE_LETTER
public static final byte UPPERCASE_LETTER
General category "Lu" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
LOWERCASE_LETTER
public static final byte LOWERCASE_LETTER
General category "Ll" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
TITLECASE_LETTER
public static final byte TITLECASE_LETTER
General category "Lt" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
MODIFIER_LETTER
public static final byte MODIFIER_LETTER
General category "Lm" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
OTHER_LETTER
public static final byte OTHER_LETTER
General category "Lo" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
NON_SPACING_MARK
public static final byte NON_SPACING_MARK
General category "Mn" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
ENCLOSING_MARK
public static final byte ENCLOSING_MARK
General category "Me" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
COMBINING_SPACING_MARK
public static final byte COMBINING_SPACING_MARK
General category "Mc" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
DECIMAL_DIGIT_NUMBER
public static final byte DECIMAL_DIGIT_NUMBER
General category "Nd" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
LETTER_NUMBER
public static final byte LETTER_NUMBER
General category "Nl" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
OTHER_NUMBER
public static final byte OTHER_NUMBER
General category "No" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
SPACE_SEPARATOR
public static final byte SPACE_SEPARATOR
General category "Zs" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
LINE_SEPARATOR
public static final byte LINE_SEPARATOR
General category "Zl" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
PARAGRAPH_SEPARATOR
public static final byte PARAGRAPH_SEPARATOR
General category "Zp" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
CONTROL
public static final byte CONTROL
General category "Cc" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
FORMAT
public static final byte FORMAT
General category "Cf" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
PRIVATE_USE
public static final byte PRIVATE_USE
General category "Co" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
SURROGATE
public static final byte SURROGATE
General category "Cs" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
DASH_PUNCTUATION
public static final byte DASH_PUNCTUATION
General category "Pd" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
START_PUNCTUATION
public static final byte START_PUNCTUATION
General category "Ps" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
END_PUNCTUATION
public static final byte END_PUNCTUATION
General category "Pe" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
CONNECTOR_PUNCTUATION
public static final byte CONNECTOR_PUNCTUATION
General category "Pc" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
OTHER_PUNCTUATION
public static final byte OTHER_PUNCTUATION
General category "Po" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
MATH_SYMBOL
public static final byte MATH_SYMBOL
General category "Sm" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
CURRENCY_SYMBOL
public static final byte CURRENCY_SYMBOL
General category "Sc" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
MODIFIER_SYMBOL
public static final byte MODIFIER_SYMBOL
General category "Sk" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
OTHER_SYMBOL
public static final byte OTHER_SYMBOL
General category "So" in the Unicode specification.
- Since:
- 1.1
- See Also:
- Constant Field Values
INITIAL_QUOTE_PUNCTUATION
public static final byte INITIAL_QUOTE_PUNCTUATION
General category "Pi" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
FINAL_QUOTE_PUNCTUATION
public static final byte FINAL_QUOTE_PUNCTUATION
General category "Pf" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_UNDEFINED
public static final byte DIRECTIONALITY_UNDEFINED
Undefined bidirectional character type. Undefined char
values have undefined directionality in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_LEFT_TO_RIGHT
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT
Strong bidirectional character type "L" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_RIGHT_TO_LEFT
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT
Strong bidirectional character type "R" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
Strong bidirectional character type "AL" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_EUROPEAN_NUMBER
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER
Weak bidirectional character type "EN" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
Weak bidirectional character type "ES" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
Weak bidirectional character type "ET" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_ARABIC_NUMBER
public static final byte DIRECTIONALITY_ARABIC_NUMBER
Weak bidirectional character type "AN" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
public static final byte DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
Weak bidirectional character type "CS" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_NONSPACING_MARK
public static final byte DIRECTIONALITY_NONSPACING_MARK
Weak bidirectional character type "NSM" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_BOUNDARY_NEUTRAL
public static final byte DIRECTIONALITY_BOUNDARY_NEUTRAL
Weak bidirectional character type "BN" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_PARAGRAPH_SEPARATOR
public static final byte DIRECTIONALITY_PARAGRAPH_SEPARATOR
Neutral bidirectional character type "B" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_SEGMENT_SEPARATOR
public static final byte DIRECTIONALITY_SEGMENT_SEPARATOR
Neutral bidirectional character type "S" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_WHITESPACE
public static final byte DIRECTIONALITY_WHITESPACE
Neutral bidirectional character type "WS" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_OTHER_NEUTRALS
public static final byte DIRECTIONALITY_OTHER_NEUTRALS
Neutral bidirectional character type "ON" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
Strong bidirectional character type "LRE" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
Strong bidirectional character type "LRO" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
Strong bidirectional character type "RLE" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
Strong bidirectional character type "RLO" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
public static final byte DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
Weak bidirectional character type "PDF" in the Unicode specification.
- Since:
- 1.4
- See Also:
- Constant Field Values
DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE
Weak bidirectional character type "LRI" in the Unicode specification.
- Since:
- 9
- See Also:
- Constant Field Values
DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE
Weak bidirectional character type "RLI" in the Unicode specification.
- Since:
- 9
- See Also:
- Constant Field Values
DIRECTIONALITY_FIRST_STRONG_ISOLATE
public static final byte DIRECTIONALITY_FIRST_STRONG_ISOLATE
Weak bidirectional character type "FSI" in the Unicode specification.
- Since:
- 9
- See Also:
- Constant Field Values
DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
public static final byte DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
Weak bidirectional character type "PDI" in the Unicode specification.
- Since:
- 9
- See Also:
- Constant Field Values
MIN_HIGH_SURROGATE
public static final char MIN_HIGH_SURROGATE
The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uD800'
. A high-surrogate is also known as a leading-surrogate.
- Since:
- 1.5
- See Also:
- Constant Field Values
MAX_HIGH_SURROGATE
public static final char MAX_HIGH_SURROGATE
The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uDBFF'
. A high-surrogate is also known as a leading-surrogate.
- Since:
- 1.5
- See Also:
- Constant Field Values
MIN_LOW_SURROGATE
public static final char MIN_LOW_SURROGATE
The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDC00'
. A low-surrogate is also known as a trailing-surrogate.
- Since:
- 1.5
- See Also:
- Constant Field Values
MAX_LOW_SURROGATE
public static final char MAX_LOW_SURROGATE
The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDFFF'
. A low-surrogate is also known as a trailing-surrogate.
- Since:
- 1.5
- See Also:
- Constant Field Values
MIN_SURROGATE
public static final char MIN_SURROGATE
The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uD800'
.
- Since:
- 1.5
- See Also:
- Constant Field Values
MAX_SURROGATE
public static final char MAX_SURROGATE
The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uDFFF'
.
- Since:
- 1.5
- See Also:
- Constant Field Values
MIN_SUPPLEMENTARY_CODE_POINT
public static final int MIN_SUPPLEMENTARY_CODE_POINT
The minimum value of a Unicode supplementary code point, constant U+10000
.
- Since:
- 1.5
- See Also:
- Constant Field Values
MIN_CODE_POINT
public static final int MIN_CODE_POINT
The minimum value of a Unicode code point, constant U+0000
.
- Since:
- 1.5
- See Also:
- Constant Field Values
MAX_CODE_POINT
public static final int MAX_CODE_POINT
The maximum value of a Unicode code point, constant U+10FFFF
.
- Since:
- 1.5
- See Also:
- Constant Field Values
SIZE
public static final int SIZE
The number of bits used to represent a char
value in unsigned binary form, constant 16
.
- Since:
- 1.5
- See Also:
- Constant Field Values
BYTES
public static final int BYTES
The number of bytes used to represent a char
value in unsigned binary form.
- Since:
- 1.8
- See Also:
- Constant Field Values
Constructors
Character
@Deprecated(since="9") public Character(char value)
valueOf(char)
is generally a better choice, as it is likely to yield significantly better space and time performance.Constructs a newly allocated Character
object that represents the specified char
value.
- Parameters:
-
value
- the value to be represented by theCharacter
object.
Methods
valueOf
public static Character valueOf(char c)
Returns a Character
instance representing the specified char
value. If a new Character
instance is not required, this method should generally be used in preference to the constructor Character(char)
, as this method is likely to yield significantly better space and time performance by caching frequently requested values. This method will always cache values in the range
'\u0000'
to '\u007F'
, inclusive, and may cache other values outside of this range.
- Parameters:
-
c
- a char value. - Returns:
- a
Character
instance representingc
. - Since:
- 1.5
charValue
public char charValue()
Returns the value of this Character
object.
- Returns:
- the primitive
char
value represented by this object.
hashCode
public int hashCode()
Returns a hash code for this Character
; equal to the result of invoking charValue()
.
- Overrides:
-
hashCode
in classObject
- Returns:
- a hash code value for this
Character
- See Also:
-
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
hashCode
public static int hashCode(char value)
Returns a hash code for a char
value; compatible with Character.hashCode()
.
- Parameters:
-
value
- Thechar
for which to return a hash code. - Returns:
- a hash code value for a
char
value. - Since:
- 1.8
equals
public boolean equals(Object obj)
Compares this object against the specified object. The result is true
if and only if the argument is not null
and is a Character
object that represents the same char
value as this object.
- Overrides:
-
equals
in classObject
- Parameters:
-
obj
- the object to compare with. - Returns:
-
true
if the objects are the same;false
otherwise. - See Also:
-
Object.hashCode()
,HashMap
toString
public String toString()
Returns a String
object representing this Character
's value. The result is a string of length 1 whose sole component is the primitive char
value represented by this Character
object.
toString
public static String toString(char c)
Returns a String
object representing the specified char
. The result is a string of length 1 consisting solely of the specified char
.
- API Note:
- This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the
toString(int)
method. - Parameters:
-
c
- thechar
to be converted - Returns:
- the string representation of the specified
char
- Since:
- 1.4
toString
public static String toString(int codePoint)
Returns a String
object representing the specified character (Unicode code point). The result is a string of length 1 or 2, consisting solely of the specified codePoint
.
- Parameters:
-
codePoint
- thecodePoint
to be converted - Returns:
- the string representation of the specified
codePoint
- Throws:
-
IllegalArgumentException
- if the specifiedcodePoint
is not a valid Unicode code point. - Since:
- 11
isValidCodePoint
public static boolean isValidCodePoint(int codePoint)
Determines whether the specified code point is a valid Unicode code point value.
- Parameters:
-
codePoint
- the Unicode code point to be tested - Returns:
-
true
if the specified code point value is betweenMIN_CODE_POINT
andMAX_CODE_POINT
inclusive;false
otherwise. - Since:
- 1.5
isBmpCodePoint
public static boolean isBmpCodePoint(int codePoint)
Determines whether the specified character (Unicode code point) is in the Basic Multilingual Plane (BMP). Such code points can be represented using a single char
.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested - Returns:
-
true
if the specified code point is betweenMIN_VALUE
andMAX_VALUE
inclusive;false
otherwise. - Since:
- 1.7
isSupplementaryCodePoint
public static boolean isSupplementaryCodePoint(int codePoint)
Determines whether the specified character (Unicode code point) is in the supplementary character range.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested - Returns:
-
true
if the specified code point is betweenMIN_SUPPLEMENTARY_CODE_POINT
andMAX_CODE_POINT
inclusive;false
otherwise. - Since:
- 1.5
isHighSurrogate
public static boolean isHighSurrogate(char ch)
Determines if the given char
value is a Unicode high-surrogate code unit (also known as leading-surrogate code unit).
Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.
- Parameters:
-
ch
- thechar
value to be tested. - Returns:
-
true
if thechar
value is betweenMIN_HIGH_SURROGATE
andMAX_HIGH_SURROGATE
inclusive;false
otherwise. - Since:
- 1.5
- See Also:
-
isLowSurrogate(char)
,Character.UnicodeBlock.of(int)
isLowSurrogate
public static boolean isLowSurrogate(char ch)
Determines if the given char
value is a Unicode low-surrogate code unit (also known as trailing-surrogate code unit).
Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.
- Parameters:
-
ch
- thechar
value to be tested. - Returns:
-
true
if thechar
value is betweenMIN_LOW_SURROGATE
andMAX_LOW_SURROGATE
inclusive;false
otherwise. - Since:
- 1.5
- See Also:
isHighSurrogate(char)
isSurrogate
public static boolean isSurrogate(char ch)
Determines if the given char
value is a Unicode surrogate code unit.
Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.
A char value is a surrogate code unit if and only if it is either a low-surrogate code unit or a high-surrogate code unit.
- Parameters:
-
ch
- thechar
value to be tested. - Returns:
-
true
if thechar
value is betweenMIN_SURROGATE
andMAX_SURROGATE
inclusive;false
otherwise. - Since:
- 1.7
isSurrogatePair
public static boolean isSurrogatePair(char high, char low)
Determines whether the specified pair of char
values is a valid Unicode surrogate pair.
This method is equivalent to the expression:
isHighSurrogate(high) && isLowSurrogate(low)
- Parameters:
-
high
- the high-surrogate code value to be tested -
low
- the low-surrogate code value to be tested - Returns:
-
true
if the specified high and low-surrogate code values represent a valid surrogate pair;false
otherwise. - Since:
- 1.5
charCount
public static int charCount(int codePoint)
Determines the number of char
values needed to represent the specified character (Unicode code point). If the specified character is equal to or greater than 0x10000, then the method returns 2. Otherwise, the method returns 1.
This method doesn't validate the specified character to be a valid Unicode code point. The caller must validate the character value using isValidCodePoint
if necessary.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
- 2 if the character is a valid supplementary character; 1 otherwise.
- Since:
- 1.5
- See Also:
isSupplementaryCodePoint(int)
toCodePoint
public static int toCodePoint(char high, char low)
Converts the specified surrogate pair to its supplementary code point value. This method does not validate the specified surrogate pair. The caller must validate it using isSurrogatePair
if necessary.
- Parameters:
-
high
- the high-surrogate code unit -
low
- the low-surrogate code unit - Returns:
- the supplementary code point composed from the specified surrogate pair.
- Since:
- 1.5
codePointAt
public static int codePointAt(CharSequence seq, int index)
Returns the code point at the given index of the CharSequence
. If the char
value at the given index in the CharSequence
is in the high-surrogate range, the following index is less than the length of the CharSequence
, and the char
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at the given index is returned.
- Parameters:
-
seq
- a sequence ofchar
values (Unicode code units) -
index
- the index to thechar
values (Unicode code units) inseq
to be converted - Returns:
- the Unicode code point at the given index
- Throws:
-
NullPointerException
- ifseq
is null. -
IndexOutOfBoundsException
- if the valueindex
is negative or not less thanseq.length()
. - Since:
- 1.5
codePointAt
public static int codePointAt(char[] a, int index)
Returns the code point at the given index of the char
array. If the char
value at the given index in the char
array is in the high-surrogate range, the following index is less than the length of the char
array, and the char
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at the given index is returned.
- Parameters:
-
a
- thechar
array -
index
- the index to thechar
values (Unicode code units) in thechar
array to be converted - Returns:
- the Unicode code point at the given index
- Throws:
-
NullPointerException
- ifa
is null. -
IndexOutOfBoundsException
- if the valueindex
is negative or not less than the length of thechar
array. - Since:
- 1.5
codePointAt
public static int codePointAt(char[] a, int index, int limit)
Returns the code point at the given index of the char
array, where only array elements with index
less than limit
can be used. If the char
value at the given index in the char
array is in the high-surrogate range, the following index is less than the limit
, and the char
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at the given index is returned.
- Parameters:
-
a
- thechar
array -
index
- the index to thechar
values (Unicode code units) in thechar
array to be converted -
limit
- the index after the last array element that can be used in thechar
array - Returns:
- the Unicode code point at the given index
- Throws:
-
NullPointerException
- ifa
is null. -
IndexOutOfBoundsException
- if theindex
argument is negative or not less than thelimit
argument, or if thelimit
argument is negative or greater than the length of thechar
array. - Since:
- 1.5
codePointBefore
public static int codePointBefore(CharSequence seq, int index)
Returns the code point preceding the given index of the CharSequence
. If the char
value at (index - 1)
in the CharSequence
is in the low-surrogate range, (index - 2)
is not negative, and the char
value at (index - 2)
in the CharSequence
is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at (index - 1)
is returned.
- Parameters:
-
seq
- theCharSequence
instance -
index
- the index following the code point that should be returned - Returns:
- the Unicode code point value before the given index.
- Throws:
-
NullPointerException
- ifseq
is null. -
IndexOutOfBoundsException
- if theindex
argument is less than 1 or greater thanseq.length()
. - Since:
- 1.5
codePointBefore
public static int codePointBefore(char[] a, int index)
Returns the code point preceding the given index of the char
array. If the char
value at (index - 1)
in the char
array is in the low-surrogate range, (index - 2)
is not negative, and the char
value at (index - 2)
in the char
array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at (index - 1)
is returned.
- Parameters:
-
a
- thechar
array -
index
- the index following the code point that should be returned - Returns:
- the Unicode code point value before the given index.
- Throws:
-
NullPointerException
- ifa
is null. -
IndexOutOfBoundsException
- if theindex
argument is less than 1 or greater than the length of thechar
array - Since:
- 1.5
codePointBefore
public static int codePointBefore(char[] a, int index, int start)
Returns the code point preceding the given index of the char
array, where only array elements with index
greater than or equal to start
can be used. If the char
value at (index - 1)
in the char
array is in the low-surrogate range, (index - 2)
is not less than start
, and the char
value at (index - 2)
in the char
array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at (index - 1)
is returned.
- Parameters:
-
a
- thechar
array -
index
- the index following the code point that should be returned -
start
- the index of the first array element in thechar
array - Returns:
- the Unicode code point value before the given index.
- Throws:
-
NullPointerException
- ifa
is null. -
IndexOutOfBoundsException
- if theindex
argument is not greater than thestart
argument or is greater than the length of thechar
array, or if thestart
argument is negative or not less than the length of thechar
array. - Since:
- 1.5
highSurrogate
public static char highSurrogate(int codePoint)
Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not a supplementary character, an unspecified char
is returned.
If isSupplementaryCodePoint(x)
is true
, then isHighSurrogate
(highSurrogate(x))
and toCodePoint
(highSurrogate(x),
lowSurrogate
(x)) == x
are also always true
.
- Parameters:
-
codePoint
- a supplementary character (Unicode code point) - Returns:
- the leading surrogate code unit used to represent the character in the UTF-16 encoding
- Since:
- 1.7
lowSurrogate
public static char lowSurrogate(int codePoint)
Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not a supplementary character, an unspecified char
is returned.
If isSupplementaryCodePoint(x)
is true
, then isLowSurrogate
(lowSurrogate(x))
and toCodePoint
(
highSurrogate
(x), lowSurrogate(x)) == x
are also always true
.
- Parameters:
-
codePoint
- a supplementary character (Unicode code point) - Returns:
- the trailing surrogate code unit used to represent the character in the UTF-16 encoding
- Since:
- 1.7
toChars
public static int toChars(int codePoint, char[] dst, int dstIndex)
Converts the specified character (Unicode code point) to its UTF-16 representation. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the same value is stored in dst[dstIndex]
, and 1 is returned. If the specified code point is a supplementary character, its surrogate values are stored in dst[dstIndex]
(high-surrogate) and dst[dstIndex+1]
(low-surrogate), and 2 is returned.
- Parameters:
-
codePoint
- the character (Unicode code point) to be converted. -
dst
- an array ofchar
in which thecodePoint
's UTF-16 value is stored. -
dstIndex
- the start index into thedst
array where the converted value is stored. - Returns:
- 1 if the code point is a BMP code point, 2 if the code point is a supplementary code point.
- Throws:
-
IllegalArgumentException
- if the specifiedcodePoint
is not a valid Unicode code point. -
NullPointerException
- if the specifieddst
is null. -
IndexOutOfBoundsException
- ifdstIndex
is negative or not less thandst.length
, or ifdst
atdstIndex
doesn't have enough array element(s) to store the resultingchar
value(s). (IfdstIndex
is equal todst.length-1
and the specifiedcodePoint
is a supplementary character, the high-surrogate value is not stored indst[dstIndex]
.) - Since:
- 1.5
toChars
public static char[] toChars(int codePoint)
Converts the specified character (Unicode code point) to its UTF-16 representation stored in a char
array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resulting char
array has the same value as codePoint
. If the specified code point is a supplementary code point, the resulting char
array has the corresponding surrogate pair.
- Parameters:
-
codePoint
- a Unicode code point - Returns:
- a
char
array havingcodePoint
's UTF-16 representation. - Throws:
-
IllegalArgumentException
- if the specifiedcodePoint
is not a valid Unicode code point. - Since:
- 1.5
codePointCount
public static int codePointCount(CharSequence seq, int beginIndex, int endIndex)
Returns the number of Unicode code points in the text range of the specified char sequence. The text range begins at the specified beginIndex
and extends to the char
at index endIndex - 1
. Thus the length (in char
s) of the text range is endIndex-beginIndex
. Unpaired surrogates within the text range count as one code point each.
- Parameters:
-
seq
- the char sequence -
beginIndex
- the index to the firstchar
of the text range. -
endIndex
- the index after the lastchar
of the text range. - Returns:
- the number of Unicode code points in the specified text range
- Throws:
-
NullPointerException
- ifseq
is null. -
IndexOutOfBoundsException
- if thebeginIndex
is negative, orendIndex
is larger than the length of the given sequence, orbeginIndex
is larger thanendIndex
. - Since:
- 1.5
codePointCount
public static int codePointCount(char[] a, int offset, int count)
Returns the number of Unicode code points in a subarray of the char
array argument. The offset
argument is the index of the first char
of the subarray and the count
argument specifies the length of the subarray in char
s. Unpaired surrogates within the subarray count as one code point each.
- Parameters:
-
a
- thechar
array -
offset
- the index of the firstchar
in the givenchar
array -
count
- the length of the subarray inchar
s - Returns:
- the number of Unicode code points in the specified subarray
- Throws:
-
NullPointerException
- ifa
is null. -
IndexOutOfBoundsException
- ifoffset
orcount
is negative, or ifoffset + count
is larger than the length of the given array. - Since:
- 1.5
offsetByCodePoints
public static int offsetByCodePoints(CharSequence seq, int index, int codePointOffset)
Returns the index within the given char sequence that is offset from the given index
by codePointOffset
code points. Unpaired surrogates within the text range given by index
and codePointOffset
count as one code point each.
- Parameters:
-
seq
- the char sequence -
index
- the index to be offset -
codePointOffset
- the offset in code points - Returns:
- the index within the char sequence
- Throws:
-
NullPointerException
- ifseq
is null. -
IndexOutOfBoundsException
- ifindex
is negative or larger then the length of the char sequence, or ifcodePointOffset
is positive and the subsequence starting withindex
has fewer thancodePointOffset
code points, or ifcodePointOffset
is negative and the subsequence beforeindex
has fewer than the absolute value ofcodePointOffset
code points. - Since:
- 1.5
offsetByCodePoints
public static int offsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset)
Returns the index within the given char
subarray that is offset from the given index
by codePointOffset
code points. The start
and count
arguments specify a subarray of the char
array. Unpaired surrogates within the text range given by index
and codePointOffset
count as one code point each.
- Parameters:
-
a
- thechar
array -
start
- the index of the firstchar
of the subarray -
count
- the length of the subarray inchar
s -
index
- the index to be offset -
codePointOffset
- the offset in code points - Returns:
- the index within the subarray
- Throws:
-
NullPointerException
- ifa
is null. -
IndexOutOfBoundsException
- ifstart
orcount
is negative, or ifstart + count
is larger than the length of the given array, or ifindex
is less thanstart
or larger thenstart + count
, or ifcodePointOffset
is positive and the text range starting withindex
and ending withstart + count - 1
has fewer thancodePointOffset
code points, or ifcodePointOffset
is negative and the text range starting withstart
and ending withindex - 1
has fewer than the absolute value ofcodePointOffset
code points. - Since:
- 1.5
isLowerCase
public static boolean isLowerCase(char ch)
Determines if the specified character is a lowercase character.
A character is lowercase if its general category type, provided by Character.getType(ch)
, is LOWERCASE_LETTER
, or it has contributory property Other_Lowercase as defined by the Unicode Standard.
The following are examples of lowercase characters:
a b c d e f g h i j k l m n o p q r s t u v w x y z '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6' '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE' '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6' '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'
Many other Unicode characters are lowercase too.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLowerCase(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is lowercase;false
otherwise. - See Also:
-
isLowerCase(char)
,isTitleCase(char)
,toLowerCase(char)
,getType(char)
isLowerCase
public static boolean isLowerCase(int codePoint)
Determines if the specified character (Unicode code point) is a lowercase character.
A character is lowercase if its general category type, provided by getType(codePoint)
, is LOWERCASE_LETTER
, or it has contributory property Other_Lowercase as defined by the Unicode Standard.
The following are examples of lowercase characters:
a b c d e f g h i j k l m n o p q r s t u v w x y z '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6' '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE' '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6' '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'
Many other Unicode characters are lowercase too.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is lowercase;false
otherwise. - Since:
- 1.5
- See Also:
-
isLowerCase(int)
,isTitleCase(int)
,toLowerCase(int)
,getType(int)
isUpperCase
public static boolean isUpperCase(char ch)
Determines if the specified character is an uppercase character.
A character is uppercase if its general category type, provided by Character.getType(ch)
, is UPPERCASE_LETTER
. or it has contributory property Other_Uppercase as defined by the Unicode Standard.
The following are examples of uppercase characters:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7' '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF' '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8' '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'
Many other Unicode characters are uppercase too.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUpperCase(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is uppercase;false
otherwise. - Since:
- 1.0
- See Also:
-
isLowerCase(char)
,isTitleCase(char)
,toUpperCase(char)
,getType(char)
isUpperCase
public static boolean isUpperCase(int codePoint)
Determines if the specified character (Unicode code point) is an uppercase character.
A character is uppercase if its general category type, provided by getType(codePoint)
, is UPPERCASE_LETTER
, or it has contributory property Other_Uppercase as defined by the Unicode Standard.
The following are examples of uppercase characters:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7' '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF' '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8' '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'
Many other Unicode characters are uppercase too.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is uppercase;false
otherwise. - Since:
- 1.5
- See Also:
-
isLowerCase(int)
,isTitleCase(int)
,toUpperCase(int)
,getType(int)
isTitleCase
public static boolean isTitleCase(char ch)
Determines if the specified character is a titlecase character.
A character is a titlecase character if its general category type, provided by Character.getType(ch)
, is TITLECASE_LETTER
.
Some characters look like pairs of Latin letters. For example, there is an uppercase letter that looks like "LJ" and has a corresponding lowercase letter that looks like "lj". A third form, which looks like "Lj", is the appropriate form to use when rendering a word in lowercase with initial capitals, as for a book title.
These are some of the Unicode characters for which this method returns true
:
-
LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON
-
LATIN CAPITAL LETTER L WITH SMALL LETTER J
-
LATIN CAPITAL LETTER N WITH SMALL LETTER J
-
LATIN CAPITAL LETTER D WITH SMALL LETTER Z
Many other Unicode characters are titlecase too.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isTitleCase(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is titlecase;false
otherwise. - Since:
- 1.0.2
- See Also:
-
isLowerCase(char)
,isUpperCase(char)
,toTitleCase(char)
,getType(char)
isTitleCase
public static boolean isTitleCase(int codePoint)
Determines if the specified character (Unicode code point) is a titlecase character.
A character is a titlecase character if its general category type, provided by getType(codePoint)
, is TITLECASE_LETTER
.
Some characters look like pairs of Latin letters. For example, there is an uppercase letter that looks like "LJ" and has a corresponding lowercase letter that looks like "lj". A third form, which looks like "Lj", is the appropriate form to use when rendering a word in lowercase with initial capitals, as for a book title.
These are some of the Unicode characters for which this method returns true
:
-
LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON
-
LATIN CAPITAL LETTER L WITH SMALL LETTER J
-
LATIN CAPITAL LETTER N WITH SMALL LETTER J
-
LATIN CAPITAL LETTER D WITH SMALL LETTER Z
Many other Unicode characters are titlecase too.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is titlecase;false
otherwise. - Since:
- 1.5
- See Also:
-
isLowerCase(int)
,isUpperCase(int)
,toTitleCase(int)
,getType(int)
isDigit
public static boolean isDigit(char ch)
Determines if the specified character is a digit.
A character is a digit if its general category type, provided by Character.getType(ch)
, is DECIMAL_DIGIT_NUMBER
.
Some Unicode character ranges that contain digits:
-
'\u0030'
through'\u0039'
, ISO-LATIN-1 digits ('0'
through'9'
) -
'\u0660'
through'\u0669'
, Arabic-Indic digits -
'\u06F0'
through'\u06F9'
, Extended Arabic-Indic digits -
'\u0966'
through'\u096F'
, Devanagari digits -
'\uFF10'
through'\uFF19'
, Fullwidth digits
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isDigit(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is a digit;false
otherwise. - See Also:
-
digit(char, int)
,forDigit(int, int)
,getType(char)
isDigit
public static boolean isDigit(int codePoint)
Determines if the specified character (Unicode code point) is a digit.
A character is a digit if its general category type, provided by getType(codePoint)
, is DECIMAL_DIGIT_NUMBER
.
Some Unicode character ranges that contain digits:
-
'\u0030'
through'\u0039'
, ISO-LATIN-1 digits ('0'
through'9'
) -
'\u0660'
through'\u0669'
, Arabic-Indic digits -
'\u06F0'
through'\u06F9'
, Extended Arabic-Indic digits -
'\u0966'
through'\u096F'
, Devanagari digits -
'\uFF10'
through'\uFF19'
, Fullwidth digits
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is a digit;false
otherwise. - Since:
- 1.5
- See Also:
-
forDigit(int, int)
,getType(int)
isDefined
public static boolean isDefined(char ch)
Determines if a character is defined in Unicode.
A character is defined if at least one of the following is true:
- It has an entry in the UnicodeData file.
- It has a value in a range defined by the UnicodeData file.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isDefined(int)
method.
- Parameters:
-
ch
- the character to be tested - Returns:
-
true
if the character has a defined meaning in Unicode;false
otherwise. - Since:
- 1.0.2
- See Also:
-
isDigit(char)
,isLetter(char)
,isLetterOrDigit(char)
,isLowerCase(char)
,isTitleCase(char)
,isUpperCase(char)
isDefined
public static boolean isDefined(int codePoint)
Determines if a character (Unicode code point) is defined in Unicode.
A character is defined if at least one of the following is true:
- It has an entry in the UnicodeData file.
- It has a value in a range defined by the UnicodeData file.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character has a defined meaning in Unicode;false
otherwise. - Since:
- 1.5
- See Also:
-
isDigit(int)
,isLetter(int)
,isLetterOrDigit(int)
,isLowerCase(int)
,isTitleCase(int)
,isUpperCase(int)
isLetter
public static boolean isLetter(char ch)
Determines if the specified character is a letter.
A character is considered to be a letter if its general category type, provided by Character.getType(ch)
, is any of the following:
-
UPPERCASE_LETTER
-
LOWERCASE_LETTER
-
TITLECASE_LETTER
-
MODIFIER_LETTER
-
OTHER_LETTER
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLetter(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is a letter;false
otherwise. - See Also:
-
isDigit(char)
,isJavaIdentifierStart(char)
,isJavaLetter(char)
,isJavaLetterOrDigit(char)
,isLetterOrDigit(char)
,isLowerCase(char)
,isTitleCase(char)
,isUnicodeIdentifierStart(char)
,isUpperCase(char)
isLetter
public static boolean isLetter(int codePoint)
Determines if the specified character (Unicode code point) is a letter.
A character is considered to be a letter if its general category type, provided by getType(codePoint)
, is any of the following:
-
UPPERCASE_LETTER
-
LOWERCASE_LETTER
-
TITLECASE_LETTER
-
MODIFIER_LETTER
-
OTHER_LETTER
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is a letter;false
otherwise. - Since:
- 1.5
- See Also:
-
isDigit(int)
,isJavaIdentifierStart(int)
,isLetterOrDigit(int)
,isLowerCase(int)
,isTitleCase(int)
,isUnicodeIdentifierStart(int)
,isUpperCase(int)
isLetterOrDigit
public static boolean isLetterOrDigit(char ch)
Determines if the specified character is a letter or digit.
A character is considered to be a letter or digit if either Character.isLetter(char ch)
or Character.isDigit(char ch)
returns true
for the character.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLetterOrDigit(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is a letter or digit;false
otherwise. - Since:
- 1.0.2
- See Also:
-
isDigit(char)
,isJavaIdentifierPart(char)
,isJavaLetter(char)
,isJavaLetterOrDigit(char)
,isLetter(char)
,isUnicodeIdentifierPart(char)
isLetterOrDigit
public static boolean isLetterOrDigit(int codePoint)
Determines if the specified character (Unicode code point) is a letter or digit.
A character is considered to be a letter or digit if either isLetter(codePoint)
or isDigit(codePoint)
returns true
for the character.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is a letter or digit;false
otherwise. - Since:
- 1.5
- See Also:
-
isDigit(int)
,isJavaIdentifierPart(int)
,isLetter(int)
,isUnicodeIdentifierPart(int)
isJavaLetter
@Deprecated(since="1.1") public static boolean isJavaLetter(char ch)
Determines if the specified character is permissible as the first character in a Java identifier.
A character may start a Java identifier if and only if one of the following conditions is true:
-
isLetter(ch)
returnstrue
-
getType(ch)
returnsLETTER_NUMBER
-
ch
is a currency symbol (such as'$'
) -
ch
is a connecting punctuation character (such as'_'
).
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character may start a Java identifier;false
otherwise. - Since:
- 1.0.2
- See Also:
-
isJavaLetterOrDigit(char)
,isJavaIdentifierStart(char)
,isJavaIdentifierPart(char)
,isLetter(char)
,isLetterOrDigit(char)
,isUnicodeIdentifierStart(char)
isJavaLetterOrDigit
@Deprecated(since="1.1") public static boolean isJavaLetterOrDigit(char ch)
Determines if the specified character may be part of a Java identifier as other than the first character.
A character may be part of a Java identifier if and only if one of the following conditions is true:
- it is a letter
- it is a currency symbol (such as
'$'
) - it is a connecting punctuation character (such as
'_'
) - it is a digit
- it is a numeric letter (such as a Roman numeral character)
- it is a combining mark
- it is a non-spacing mark
-
isIdentifierIgnorable
returnstrue
for the character.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character may be part of a Java identifier;false
otherwise. - Since:
- 1.0.2
- See Also:
-
isJavaLetter(char)
,isJavaIdentifierStart(char)
,isJavaIdentifierPart(char)
,isLetter(char)
,isLetterOrDigit(char)
,isUnicodeIdentifierPart(char)
,isIdentifierIgnorable(char)
isAlphabetic
public static boolean isAlphabetic(int codePoint)
Determines if the specified character (Unicode code point) is an alphabet.
A character is considered to be alphabetic if its general category type, provided by getType(codePoint)
, is any of the following:
-
UPPERCASE_LETTER
-
LOWERCASE_LETTER
-
TITLECASE_LETTER
-
MODIFIER_LETTER
-
OTHER_LETTER
-
LETTER_NUMBER
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is a Unicode alphabet character,false
otherwise. - Since:
- 1.7
isIdeographic
public static boolean isIdeographic(int codePoint)
Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is a Unicode ideograph character,false
otherwise. - Since:
- 1.7
isJavaIdentifierStart
public static boolean isJavaIdentifierStart(char ch)
Determines if the specified character is permissible as the first character in a Java identifier.
A character may start a Java identifier if and only if one of the following conditions is true:
-
isLetter(ch)
returnstrue
-
getType(ch)
returnsLETTER_NUMBER
-
ch
is a currency symbol (such as'$'
) -
ch
is a connecting punctuation character (such as'_'
).
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isJavaIdentifierStart(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character may start a Java identifier;false
otherwise. - Since:
- 1.1
- See Also:
-
isJavaIdentifierPart(char)
,isLetter(char)
,isUnicodeIdentifierStart(char)
,SourceVersion.isIdentifier(CharSequence)
isJavaIdentifierStart
public static boolean isJavaIdentifierStart(int codePoint)
Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.
A character may start a Java identifier if and only if one of the following conditions is true:
-
isLetter(codePoint)
returnstrue
-
getType(codePoint)
returnsLETTER_NUMBER
- the referenced character is a currency symbol (such as
'$'
) - the referenced character is a connecting punctuation character (such as
'_'
).
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character may start a Java identifier;false
otherwise. - Since:
- 1.5
- See Also:
-
isJavaIdentifierPart(int)
,isLetter(int)
,isUnicodeIdentifierStart(int)
,SourceVersion.isIdentifier(CharSequence)
isJavaIdentifierPart
public static boolean isJavaIdentifierPart(char ch)
Determines if the specified character may be part of a Java identifier as other than the first character.
A character may be part of a Java identifier if any of the following conditions are true:
- it is a letter
- it is a currency symbol (such as
'$'
) - it is a connecting punctuation character (such as
'_'
) - it is a digit
- it is a numeric letter (such as a Roman numeral character)
- it is a combining mark
- it is a non-spacing mark
-
isIdentifierIgnorable
returnstrue
for the character
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isJavaIdentifierPart(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character may be part of a Java identifier;false
otherwise. - Since:
- 1.1
- See Also:
-
isIdentifierIgnorable(char)
,isJavaIdentifierStart(char)
,isLetterOrDigit(char)
,isUnicodeIdentifierPart(char)
,SourceVersion.isIdentifier(CharSequence)
isJavaIdentifierPart
public static boolean isJavaIdentifierPart(int codePoint)
Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.
A character may be part of a Java identifier if any of the following conditions are true:
- it is a letter
- it is a currency symbol (such as
'$'
) - it is a connecting punctuation character (such as
'_'
) - it is a digit
- it is a numeric letter (such as a Roman numeral character)
- it is a combining mark
- it is a non-spacing mark
-
isIdentifierIgnorable(codePoint)
returnstrue
for the code point
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character may be part of a Java identifier;false
otherwise. - Since:
- 1.5
- See Also:
-
isIdentifierIgnorable(int)
,isJavaIdentifierStart(int)
,isLetterOrDigit(int)
,isUnicodeIdentifierPart(int)
,SourceVersion.isIdentifier(CharSequence)
isUnicodeIdentifierStart
public static boolean isUnicodeIdentifierStart(char ch)
Determines if the specified character is permissible as the first character in a Unicode identifier.
A character may start a Unicode identifier if and only if one of the following conditions is true:
-
isLetter(ch)
returnstrue
-
getType(ch)
returnsLETTER_NUMBER
.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUnicodeIdentifierStart(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character may start a Unicode identifier;false
otherwise. - Since:
- 1.1
- See Also:
-
isJavaIdentifierStart(char)
,isLetter(char)
,isUnicodeIdentifierPart(char)
isUnicodeIdentifierStart
public static boolean isUnicodeIdentifierStart(int codePoint)
Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.
A character may start a Unicode identifier if and only if one of the following conditions is true:
-
isLetter(codePoint)
returnstrue
-
getType(codePoint)
returnsLETTER_NUMBER
.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character may start a Unicode identifier;false
otherwise. - Since:
- 1.5
- See Also:
-
isJavaIdentifierStart(int)
,isLetter(int)
,isUnicodeIdentifierPart(int)
isUnicodeIdentifierPart
public static boolean isUnicodeIdentifierPart(char ch)
Determines if the specified character may be part of a Unicode identifier as other than the first character.
A character may be part of a Unicode identifier if and only if one of the following statements is true:
- it is a letter
- it is a connecting punctuation character (such as
'_'
) - it is a digit
- it is a numeric letter (such as a Roman numeral character)
- it is a combining mark
- it is a non-spacing mark
-
isIdentifierIgnorable
returnstrue
for this character.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUnicodeIdentifierPart(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character may be part of a Unicode identifier;false
otherwise. - Since:
- 1.1
- See Also:
-
isIdentifierIgnorable(char)
,isJavaIdentifierPart(char)
,isLetterOrDigit(char)
,isUnicodeIdentifierStart(char)
isUnicodeIdentifierPart
public static boolean isUnicodeIdentifierPart(int codePoint)
Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.
A character may be part of a Unicode identifier if and only if one of the following statements is true:
- it is a letter
- it is a connecting punctuation character (such as
'_'
) - it is a digit
- it is a numeric letter (such as a Roman numeral character)
- it is a combining mark
- it is a non-spacing mark
-
isIdentifierIgnorable
returnstrue
for this character.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character may be part of a Unicode identifier;false
otherwise. - Since:
- 1.5
- See Also:
-
isIdentifierIgnorable(int)
,isJavaIdentifierPart(int)
,isLetterOrDigit(int)
,isUnicodeIdentifierStart(int)
isIdentifierIgnorable
public static boolean isIdentifierIgnorable(char ch)
Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:
- ISO control characters that are not whitespace
-
'\u0000'
through'\u0008'
-
'\u000E'
through'\u001B'
-
'\u007F'
through'\u009F'
-
- all characters that have the
FORMAT
general category value
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isIdentifierIgnorable(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is an ignorable control character that may be part of a Java or Unicode identifier;false
otherwise. - Since:
- 1.1
- See Also:
-
isJavaIdentifierPart(char)
,isUnicodeIdentifierPart(char)
isIdentifierIgnorable
public static boolean isIdentifierIgnorable(int codePoint)
Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:
- ISO control characters that are not whitespace
-
'\u0000'
through'\u0008'
-
'\u000E'
through'\u001B'
-
'\u007F'
through'\u009F'
-
- all characters that have the
FORMAT
general category value
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is an ignorable control character that may be part of a Java or Unicode identifier;false
otherwise. - Since:
- 1.5
- See Also:
-
isJavaIdentifierPart(int)
,isUnicodeIdentifierPart(int)
toLowerCase
public static char toLowerCase(char ch)
Converts the character argument to lowercase using case mapping information from the UnicodeData file.
Note that Character.isLowerCase(Character.toLowerCase(ch))
does not always return true
for some ranges of characters, particularly those that are symbols or ideographs.
In general, String.toLowerCase()
should be used to map characters to lowercase. String
case mapping methods have several benefits over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toLowerCase(int)
method.
- Parameters:
-
ch
- the character to be converted. - Returns:
- the lowercase equivalent of the character, if any; otherwise, the character itself.
- See Also:
-
isLowerCase(char)
,String.toLowerCase()
toLowerCase
public static int toLowerCase(int codePoint)
Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.
Note that Character.isLowerCase(Character.toLowerCase(codePoint))
does not always return true
for some ranges of characters, particularly those that are symbols or ideographs.
In general, String.toLowerCase()
should be used to map characters to lowercase. String
case mapping methods have several benefits over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
- Parameters:
-
codePoint
- the character (Unicode code point) to be converted. - Returns:
- the lowercase equivalent of the character (Unicode code point), if any; otherwise, the character itself.
- Since:
- 1.5
- See Also:
-
isLowerCase(int)
,String.toLowerCase()
toUpperCase
public static char toUpperCase(char ch)
Converts the character argument to uppercase using case mapping information from the UnicodeData file.
Note that Character.isUpperCase(Character.toUpperCase(ch))
does not always return true
for some ranges of characters, particularly those that are symbols or ideographs.
In general, String.toUpperCase()
should be used to map characters to uppercase. String
case mapping methods have several benefits over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toUpperCase(int)
method.
- Parameters:
-
ch
- the character to be converted. - Returns:
- the uppercase equivalent of the character, if any; otherwise, the character itself.
- See Also:
-
isUpperCase(char)
,String.toUpperCase()
toUpperCase
public static int toUpperCase(int codePoint)
Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.
Note that Character.isUpperCase(Character.toUpperCase(codePoint))
does not always return true
for some ranges of characters, particularly those that are symbols or ideographs.
In general, String.toUpperCase()
should be used to map characters to uppercase. String
case mapping methods have several benefits over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
- Parameters:
-
codePoint
- the character (Unicode code point) to be converted. - Returns:
- the uppercase equivalent of the character, if any; otherwise, the character itself.
- Since:
- 1.5
- See Also:
-
isUpperCase(int)
,String.toUpperCase()
toTitleCase
public static char toTitleCase(char ch)
Converts the character argument to titlecase using case mapping information from the UnicodeData file. If a character has no explicit titlecase mapping and is not itself a titlecase char according to UnicodeData, then the uppercase mapping is returned as an equivalent titlecase mapping. If the char
argument is already a titlecase char
, the same char
value will be returned.
Note that Character.isTitleCase(Character.toTitleCase(ch))
does not always return true
for some ranges of characters.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toTitleCase(int)
method.
- Parameters:
-
ch
- the character to be converted. - Returns:
- the titlecase equivalent of the character, if any; otherwise, the character itself.
- Since:
- 1.0.2
- See Also:
-
isTitleCase(char)
,toLowerCase(char)
,toUpperCase(char)
toTitleCase
public static int toTitleCase(int codePoint)
Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file. If a character has no explicit titlecase mapping and is not itself a titlecase char according to UnicodeData, then the uppercase mapping is returned as an equivalent titlecase mapping. If the character argument is already a titlecase character, the same character value will be returned.
Note that Character.isTitleCase(Character.toTitleCase(codePoint))
does not always return true
for some ranges of characters.
- Parameters:
-
codePoint
- the character (Unicode code point) to be converted. - Returns:
- the titlecase equivalent of the character, if any; otherwise, the character itself.
- Since:
- 1.5
- See Also:
-
isTitleCase(int)
,toLowerCase(int)
,toUpperCase(int)
digit
public static int digit(char ch, int radix)
Returns the numeric value of the character ch
in the specified radix.
If the radix is not in the range MIN_RADIX
≤ radix
≤ MAX_RADIX
or if the value of ch
is not a valid digit in the specified radix, -1
is returned. A character is a valid digit if at least one of the following is true:
- The method
isDigit
istrue
of the character and the Unicode decimal digit value of the character (or its single-character decomposition) is less than the specified radix. In this case the decimal digit value is returned. - The character is one of the uppercase Latin letters
'A'
through'Z'
and its code is less thanradix + 'A' - 10
. In this case,ch - 'A' + 10
is returned. - The character is one of the lowercase Latin letters
'a'
through'z'
and its code is less thanradix + 'a' - 10
. In this case,ch - 'a' + 10
is returned. - The character is one of the fullwidth uppercase Latin letters A (
'\uFF21'
) through Z ('\uFF3A'
) and its code is less thanradix + '\uFF21' - 10
. In this case,ch - '\uFF21' + 10
is returned. - The character is one of the fullwidth lowercase Latin letters a (
'\uFF41'
) through z ('\uFF5A'
) and its code is less thanradix + '\uFF41' - 10
. In this case,ch - '\uFF41' + 10
is returned.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the digit(int, int)
method.
- Parameters:
-
ch
- the character to be converted. -
radix
- the radix. - Returns:
- the numeric value represented by the character in the specified radix.
- See Also:
-
forDigit(int, int)
,isDigit(char)
digit
public static int digit(int codePoint, int radix)
Returns the numeric value of the specified character (Unicode code point) in the specified radix.
If the radix is not in the range MIN_RADIX
≤ radix
≤ MAX_RADIX
or if the character is not a valid digit in the specified radix, -1
is returned. A character is a valid digit if at least one of the following is true:
- The method
isDigit(codePoint)
istrue
of the character and the Unicode decimal digit value of the character (or its single-character decomposition) is less than the specified radix. In this case the decimal digit value is returned. - The character is one of the uppercase Latin letters
'A'
through'Z'
and its code is less thanradix + 'A' - 10
. In this case,codePoint - 'A' + 10
is returned. - The character is one of the lowercase Latin letters
'a'
through'z'
and its code is less thanradix + 'a' - 10
. In this case,codePoint - 'a' + 10
is returned. - The character is one of the fullwidth uppercase Latin letters A (
'\uFF21'
) through Z ('\uFF3A'
) and its code is less thanradix + '\uFF21' - 10
. In this case,codePoint - '\uFF21' + 10
is returned. - The character is one of the fullwidth lowercase Latin letters a (
'\uFF41'
) through z ('\uFF5A'
) and its code is less thanradix + '\uFF41'- 10
. In this case,codePoint - '\uFF41' + 10
is returned.
- Parameters:
-
codePoint
- the character (Unicode code point) to be converted. -
radix
- the radix. - Returns:
- the numeric value represented by the character in the specified radix.
- Since:
- 1.5
- See Also:
-
forDigit(int, int)
,isDigit(int)
getNumericValue
public static int getNumericValue(char ch)
Returns the int
value that the specified Unicode character represents. For example, the character '\u216C'
(the roman numeral fifty) will return an int with a value of 50.
The letters A-Z in their uppercase ('\u0041'
through '\u005A'
), lowercase ('\u0061'
through '\u007A'
), and full width variant ('\uFF21'
through '\uFF3A'
and '\uFF41'
through '\uFF5A'
) forms have numeric values from 10 through 35. This is independent of the Unicode specification, which does not assign numeric values to these char
values.
If the character does not have a numeric value, then -1 is returned. If the character has a numeric value that cannot be represented as a nonnegative integer (for example, a fractional value), then -2 is returned.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getNumericValue(int)
method.
- Parameters:
-
ch
- the character to be converted. - Returns:
- the numeric value of the character, as a nonnegative
int
value; -2 if the character has a numeric value but the value can not be represented as a nonnegativeint
value; -1 if the character has no numeric value. - Since:
- 1.1
- See Also:
-
forDigit(int, int)
,isDigit(char)
getNumericValue
public static int getNumericValue(int codePoint)
Returns the int
value that the specified character (Unicode code point) represents. For example, the character '\u216C'
(the Roman numeral fifty) will return an int
with a value of 50.
The letters A-Z in their uppercase ('\u0041'
through '\u005A'
), lowercase ('\u0061'
through '\u007A'
), and full width variant ('\uFF21'
through '\uFF3A'
and '\uFF41'
through '\uFF5A'
) forms have numeric values from 10 through 35. This is independent of the Unicode specification, which does not assign numeric values to these char
values.
If the character does not have a numeric value, then -1 is returned. If the character has a numeric value that cannot be represented as a nonnegative integer (for example, a fractional value), then -2 is returned.
- Parameters:
-
codePoint
- the character (Unicode code point) to be converted. - Returns:
- the numeric value of the character, as a nonnegative
int
value; -2 if the character has a numeric value but the value can not be represented as a nonnegativeint
value; -1 if the character has no numeric value. - Since:
- 1.5
- See Also:
-
forDigit(int, int)
,isDigit(int)
isSpace
@Deprecated(since="1.1") public static boolean isSpace(char ch)
Determines if the specified character is ISO-LATIN-1 white space. This method returns true
for the following five characters only:
Character | Code | Name |
---|---|---|
'\t' | U+0009 | HORIZONTAL TABULATION |
'\n' | U+000A | NEW LINE |
'\f' | U+000C | FORM FEED |
'\r' | U+000D | CARRIAGE RETURN |
' ' | U+0020 | SPACE |
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is ISO-LATIN-1 white space;false
otherwise. - See Also:
-
isSpaceChar(char)
,isWhitespace(char)
isSpaceChar
public static boolean isSpaceChar(char ch)
Determines if the specified character is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode Standard. This method returns true if the character's general category type is any of the following:
-
SPACE_SEPARATOR
-
LINE_SEPARATOR
-
PARAGRAPH_SEPARATOR
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isSpaceChar(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is a space character;false
otherwise. - Since:
- 1.1
- See Also:
isWhitespace(char)
isSpaceChar
public static boolean isSpaceChar(int codePoint)
Determines if the specified character (Unicode code point) is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode Standard. This method returns true if the character's general category type is any of the following:
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is a space character;false
otherwise. - Since:
- 1.5
- See Also:
isWhitespace(int)
isWhitespace
public static boolean isWhitespace(char ch)
Determines if the specified character is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:
- It is a Unicode space character (
SPACE_SEPARATOR
,LINE_SEPARATOR
, orPARAGRAPH_SEPARATOR
) but is not also a non-breaking space ('\u00A0'
,'\u2007'
,'\u202F'
). - It is
'\t'
, U+0009 HORIZONTAL TABULATION. - It is
'\n'
, U+000A LINE FEED. - It is
'\u000B'
, U+000B VERTICAL TABULATION. - It is
'\f'
, U+000C FORM FEED. - It is
'\r'
, U+000D CARRIAGE RETURN. - It is
'\u001C'
, U+001C FILE SEPARATOR. - It is
'\u001D'
, U+001D GROUP SEPARATOR. - It is
'\u001E'
, U+001E RECORD SEPARATOR. - It is
'\u001F'
, U+001F UNIT SEPARATOR.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isWhitespace(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is a Java whitespace character;false
otherwise. - Since:
- 1.1
- See Also:
isSpaceChar(char)
isWhitespace
public static boolean isWhitespace(int codePoint)
Determines if the specified character (Unicode code point) is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:
- It is a Unicode space character (
SPACE_SEPARATOR
,LINE_SEPARATOR
, orPARAGRAPH_SEPARATOR
) but is not also a non-breaking space ('\u00A0'
,'\u2007'
,'\u202F'
). - It is
'\t'
, U+0009 HORIZONTAL TABULATION. - It is
'\n'
, U+000A LINE FEED. - It is
'\u000B'
, U+000B VERTICAL TABULATION. - It is
'\f'
, U+000C FORM FEED. - It is
'\r'
, U+000D CARRIAGE RETURN. - It is
'\u001C'
, U+001C FILE SEPARATOR. - It is
'\u001D'
, U+001D GROUP SEPARATOR. - It is
'\u001E'
, U+001E RECORD SEPARATOR. - It is
'\u001F'
, U+001F UNIT SEPARATOR.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is a Java whitespace character;false
otherwise. - Since:
- 1.5
- See Also:
isSpaceChar(int)
isISOControl
public static boolean isISOControl(char ch)
Determines if the specified character is an ISO control character. A character is considered to be an ISO control character if its code is in the range '\u0000'
through '\u001F'
or in the range '\u007F'
through '\u009F'
.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isISOControl(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
-
true
if the character is an ISO control character;false
otherwise. - Since:
- 1.1
- See Also:
-
isSpaceChar(char)
,isWhitespace(char)
isISOControl
public static boolean isISOControl(int codePoint)
Determines if the referenced character (Unicode code point) is an ISO control character. A character is considered to be an ISO control character if its code is in the range '\u0000'
through '\u001F'
or in the range '\u007F'
through '\u009F'
.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is an ISO control character;false
otherwise. - Since:
- 1.5
- See Also:
-
isSpaceChar(int)
,isWhitespace(int)
getType
public static int getType(char ch)
Returns a value indicating a character's general category.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getType(int)
method.
- Parameters:
-
ch
- the character to be tested. - Returns:
- a value of type
int
representing the character's general category. - Since:
- 1.1
- See Also:
-
COMBINING_SPACING_MARK
,CONNECTOR_PUNCTUATION
,CONTROL
,CURRENCY_SYMBOL
,DASH_PUNCTUATION
,DECIMAL_DIGIT_NUMBER
,ENCLOSING_MARK
,END_PUNCTUATION
,FINAL_QUOTE_PUNCTUATION
,FORMAT
,INITIAL_QUOTE_PUNCTUATION
,LETTER_NUMBER
,LINE_SEPARATOR
,LOWERCASE_LETTER
,MATH_SYMBOL
,MODIFIER_LETTER
,MODIFIER_SYMBOL
,NON_SPACING_MARK
,OTHER_LETTER
,OTHER_NUMBER
,OTHER_PUNCTUATION
,OTHER_SYMBOL
,PARAGRAPH_SEPARATOR
,PRIVATE_USE
,SPACE_SEPARATOR
,START_PUNCTUATION
,SURROGATE
,TITLECASE_LETTER
,UNASSIGNED
,UPPERCASE_LETTER
getType
public static int getType(int codePoint)
Returns a value indicating a character's general category.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
- a value of type
int
representing the character's general category. - Since:
- 1.5
- See Also:
-
COMBINING_SPACING_MARK
,CONNECTOR_PUNCTUATION
,CONTROL
,CURRENCY_SYMBOL
,DASH_PUNCTUATION
,DECIMAL_DIGIT_NUMBER
,ENCLOSING_MARK
,END_PUNCTUATION
,FINAL_QUOTE_PUNCTUATION
,FORMAT
,INITIAL_QUOTE_PUNCTUATION
,LETTER_NUMBER
,LINE_SEPARATOR
,LOWERCASE_LETTER
,MATH_SYMBOL
,MODIFIER_LETTER
,MODIFIER_SYMBOL
,NON_SPACING_MARK
,OTHER_LETTER
,OTHER_NUMBER
,OTHER_PUNCTUATION
,OTHER_SYMBOL
,PARAGRAPH_SEPARATOR
,PRIVATE_USE
,SPACE_SEPARATOR
,START_PUNCTUATION
,SURROGATE
,TITLECASE_LETTER
,UNASSIGNED
,UPPERCASE_LETTER
forDigit
public static char forDigit(int digit, int radix)
Determines the character representation for a specific digit in the specified radix. If the value of radix
is not a valid radix, or the value of digit
is not a valid digit in the specified radix, the null character ('\u0000'
) is returned.
The radix
argument is valid if it is greater than or equal to MIN_RADIX
and less than or equal to MAX_RADIX
. The digit
argument is valid if 0 <= digit < radix
.
If the digit is less than 10, then '0' + digit
is returned. Otherwise, the value 'a' + digit - 10
is returned.
- Parameters:
-
digit
- the number to convert to a character. -
radix
- the radix. - Returns:
- the
char
representation of the specified digit in the specified radix. - See Also:
-
MIN_RADIX
,MAX_RADIX
,digit(char, int)
getDirectionality
public static byte getDirectionality(char ch)
Returns the Unicode directionality property for the given character. Character directionality is used to calculate the visual ordering of text. The directionality value of undefined char
values is DIRECTIONALITY_UNDEFINED
.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getDirectionality(int)
method.
- Parameters:
-
ch
-char
for which the directionality property is requested. - Returns:
- the directionality property of the
char
value. - Since:
- 1.4
- See Also:
-
DIRECTIONALITY_UNDEFINED
,DIRECTIONALITY_LEFT_TO_RIGHT
,DIRECTIONALITY_RIGHT_TO_LEFT
,DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
,DIRECTIONALITY_EUROPEAN_NUMBER
,DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
,DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
,DIRECTIONALITY_ARABIC_NUMBER
,DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
,DIRECTIONALITY_NONSPACING_MARK
,DIRECTIONALITY_BOUNDARY_NEUTRAL
,DIRECTIONALITY_PARAGRAPH_SEPARATOR
,DIRECTIONALITY_SEGMENT_SEPARATOR
,DIRECTIONALITY_WHITESPACE
,DIRECTIONALITY_OTHER_NEUTRALS
,DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
,DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
,DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
,DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
,DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
,DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE
,DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE
,DIRECTIONALITY_FIRST_STRONG_ISOLATE
,DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
getDirectionality
public static byte getDirectionality(int codePoint)
Returns the Unicode directionality property for the given character (Unicode code point). Character directionality is used to calculate the visual ordering of text. The directionality value of undefined character is DIRECTIONALITY_UNDEFINED
.
- Parameters:
-
codePoint
- the character (Unicode code point) for which the directionality property is requested. - Returns:
- the directionality property of the character.
- Since:
- 1.5
- See Also:
-
DIRECTIONALITY_UNDEFINED
,DIRECTIONALITY_LEFT_TO_RIGHT
,DIRECTIONALITY_RIGHT_TO_LEFT
,DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
,DIRECTIONALITY_EUROPEAN_NUMBER
,DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
,DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
,DIRECTIONALITY_ARABIC_NUMBER
,DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
,DIRECTIONALITY_NONSPACING_MARK
,DIRECTIONALITY_BOUNDARY_NEUTRAL
,DIRECTIONALITY_PARAGRAPH_SEPARATOR
,DIRECTIONALITY_SEGMENT_SEPARATOR
,DIRECTIONALITY_WHITESPACE
,DIRECTIONALITY_OTHER_NEUTRALS
,DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
,DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
,DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
,DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
,DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
,DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE
,DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE
,DIRECTIONALITY_FIRST_STRONG_ISOLATE
,DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
isMirrored
public static boolean isMirrored(char ch)
Determines whether the character is mirrored according to the Unicode specification. Mirrored characters should have their glyphs horizontally mirrored when displayed in text that is right-to-left. For example, '\u0028'
LEFT PARENTHESIS is semantically defined to be an opening parenthesis. This will appear as a "(" in text that is left-to-right but as a ")" in text that is right-to-left.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isMirrored(int)
method.
- Parameters:
-
ch
-char
for which the mirrored property is requested - Returns:
-
true
if the char is mirrored,false
if thechar
is not mirrored or is not defined. - Since:
- 1.4
isMirrored
public static boolean isMirrored(int codePoint)
Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification. Mirrored characters should have their glyphs horizontally mirrored when displayed in text that is right-to-left. For example, '\u0028'
LEFT PARENTHESIS is semantically defined to be an opening parenthesis. This will appear as a "(" in text that is left-to-right but as a ")" in text that is right-to-left.
- Parameters:
-
codePoint
- the character (Unicode code point) to be tested. - Returns:
-
true
if the character is mirrored,false
if the character is not mirrored or is not defined. - Since:
- 1.5
compareTo
public int compareTo(Character anotherCharacter)
Compares two Character
objects numerically.
- Specified by:
-
compareTo
in interfaceComparable<Character>
- Parameters:
-
anotherCharacter
- theCharacter
to be compared. - Returns:
- the value
0
if the argumentCharacter
is equal to thisCharacter
; a value less than0
if thisCharacter
is numerically less than theCharacter
argument; and a value greater than0
if thisCharacter
is numerically greater than theCharacter
argument (unsigned comparison). Note that this is strictly a numerical comparison; it is not locale-dependent. - Since:
- 1.2
compare
public static int compare(char x, char y)
Compares two char
values numerically. The value returned is identical to what would be returned by:
Character.valueOf(x).compareTo(Character.valueOf(y))
- Parameters:
-
x
- the firstchar
to compare -
y
- the secondchar
to compare - Returns:
- the value
0
ifx == y
; a value less than0
ifx < y
; and a value greater than0
ifx > y
- Since:
- 1.7
reverseBytes
public static char reverseBytes(char ch)
Returns the value obtained by reversing the order of the bytes in the specified char
value.
- Parameters:
-
ch
- Thechar
of which to reverse the byte order. - Returns:
- the value obtained by reversing (or, equivalently, swapping) the bytes in the specified
char
value. - Since:
- 1.5
getName
public static String getName(int codePoint)
Returns the Unicode name of the specified character codePoint
, or null if the code point is unassigned
.
Note: if the specified character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), the returned name is the same as the result of expression.
Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);
- Parameters:
-
codePoint
- the character (Unicode code point) - Returns:
- the Unicode name of the specified character, or null if the code point is unassigned.
- Throws:
-
IllegalArgumentException
- if the specifiedcodePoint
is not a valid Unicode code point. - Since:
- 1.7
codePointOf
public static int codePointOf(String name)
Returns the code point value of the Unicode character specified by the given Unicode character name.
Note: if a character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), its name is defined as the result of expression
Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);
The name
matching is case insensitive, with any leading and trailing whitespace character removed.
- Parameters:
-
name
- the Unicode character name - Returns:
- the code point value of the character specified by its name.
- Throws:
-
IllegalArgumentException
- if the specifiedname
is not a valid Unicode character name. -
NullPointerException
- ifname
isnull
- Since:
- 9
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html